1. Field of the Invention
The present invention relates to a process for producing 1-aminopyrrolidine, and also to 1-aminopyrrolidine which is produced by the process.
2. Discussion of the Background
1-Aminopyrrolidine is a useful compound as a starting material or synthetic intermediate for tetrahydropyridazine derivatives used as herbicides. 1-Aminopyrrolidine is also a useful compound as a reducing agent, a deoxidizer, a scale inhibitor, an epoxy hardener, or the like.
With regard to the production process of 1-aminopyrrolidine, a process in which hydrazine hydrate is dissolved in isopropanol and then 1,4-dihalobutane and alkali are added thereto under heating is known (see SU 1525151-A1). However, the yield and purity of 1-aminopyrrolidine obtained by the process are not satisfactory.
Additionally, since isopropanol used in the process forms an azeotropic mixture with water in the reaction system, an anhydrous state is resulted in the reaction system during the reaction upon heating and, therefore, it is unavoidable that hydrazine hydrate used as a starting material changes to very toxic and dangerous anhydrous hydrazine whereby there is a problem in the operation.
Moreover, a small amount of isopropanol remains in the crude reaction product together with 1-aminopyrrolidine and fractionation of isopropanol from 1-aminopyrrolidine is very difficult whereby it is unavoidable that yield and purity of the desired product further decrease.